Hello,
In your case, since you are Migrating Symantec Endpoint Protection Manager (SEPM) 11.0.6 to Symantec Endpoint Protection Manager 12.1.2
You may need to download - "Symantec_Endpoint_Protection_12.1.2_Part1_Installation_EN" and not SEPM_MP1_12.1.2_EN. from https://symantec.flexnetoperations.com (earlier - Symantec FileConnect website.)
For you the Migration path is:
SEP 11.0.6 >> SEP 12.1.RU2 >> SEP 12.1 RU2 MP1
Upgrade and Migration paths
Symantec Endpoint Protection 12.1.2 (RU2) can upgrade seamlessly over the following:
- Symantec Endpoint Protection 12.1.1101.401 (RU1 MP1)
- Symantec Endpoint Protection 12.1.1000.157 (RU1)
- Symantec Endpoint Protection 12.1.671.4971 (RTM)
- Symantec Endpoint Protection 11.x (can be upgraded to enterprise version only)
- Symantec Endpoint Protection Small Business Edition 12.0
Check these Articles:
Best practices for upgrading to Symantec Endpoint Protection 12.1.2
http://www.symantec.com/docs/TECH163700
Latest Symantec Endpoint Protection Releases - SEP 12.1 RU2 and SEP 11.0 RU7 MP3
https://www-secure.symantec.com/connect/articles/latest-symantec-endpoint-protection-releases-symantec-endpoint-protection-121-ru2
Understanding the Downloads of Symantec Endpoint Protection (SEP) 12.1 available on Symantec FileConnect website.
https://www-secure.symantec.com/connect/articles/understanding-downloads-symantec-endpoint-protection-sep-121-available-symantec-fileconnect
Hope that helps!!